Performance of a Multipurpose Filter for Simultaneous Removal of Ammonium and Suspended Solids as a Polishing Stage for a Domestic Wastewater Plant Effluent

Abstract

A multipurpose filter column was studied as a polishing stage for the simultaneous removal of ammonium and suspended solids from a secondary domestic wastewater effluent. The multipurpose filter consisted of sand as the regular filter material, primarily for the purpose of suspended solids removal, and an ammonium selective natural zeolite, clinoptilolite, for the removal of ammonium. A Turkish clinoptilolite from the Bigadic region was used in the experiments. The capacity of the clinoptilolite was determined by isotherm analysis to be 10.4 mg/g for 20 mg/lt initial wastewater ammonium concentration at pH 7.3 with 0.5-1 mm diameter. In the continuous runs, the multipurpose filter unit was operated down flow with 50% of the unit consisting of clinoptilolite in the upper layer, and 50% sand in the lower both with a grain size range of 0.5-1 mm. The results have revealed that simultaneous removal of 100% of the ammonium and 75% of the suspended solids removal be achieved in the multipurpose filter unit for a working period of 38 hours. The success of this proposal could lend an alternative both for the upgrading of existing treatment plants and for polishing for ammonium and suspended solids rate by using one compact unit.